Method for reducing radio ranging errors due to clock frequency offsets

摘要

A method reduces errors in two-way ranging between transceivers due to a frequency offset. A first transceiver measures a time CA1 between transmitting a request frame and receiving a reply frame, and a time CA2 between receiving a first information bit of the reply frame and receiving a last information bit of the reply frame. A second transceiver measures a time CB2 between receiving the request frame and transmitting the last information bit of the reply frame, and a time CB1 between receiving a first information bit of the request frame and a last information bit of the request frame. A correction factor ${\mathrm{alpha}}_c=\sqrt{\frac{C_{B1}}{C_{A2}}}$ is applied according to ${\hat{C}}_{B2}=C_{B2}/{\mathrm{alpha}}_c,$ and the one-way time is ${\hat{T}}_t=\frac{C_{A1}-{\hat{C}}_{B2}}{2}{T}_i.$ where Ti is an ideal period of the clocks of the transceivers.